Environmental context shapes the long‐term role of nutrients in driving producer community trajectories in a top‐down dominated marine ecosystem

1. Two predominant anthropogenic impacts on ecosystems, nutrient enrichment and the removal of consumers, are predicted to interact in their effects on producer diversity. Yet, measures of diversity alone may not capture changes occurring in the underlying mechanisms structuring communities. Furthermore, evidence for these interactions in rocky intertidal systems is mixed and may be confounded by variable baseline productivity or short experimental durations that do not capture seasonality, environmental heterogeneity or successional processes. 

2. We conducted a 2-year experiment examining the main and interactive effects of nutrients and herbivores in a low-productivity environment on the northern shore of Cook Strait near Wellington, New Zealand. We explicitly accounted for the small-scale spatial environmental heterogeneity characteristic of rocky shores. 

3. Rapid and dramatic shifts in diversity metrics and cover of algal communities in the first year were driven by removal ...